Three-dimensional printing with wetting agent

Abstract

A multi-fluid kit for three-dimensional printing can include a wetting agent and a binding agent. The wetting agent can include from about 5 wt % to about 80 wt % water-miscible hydroxyl-containing solvent and from about 20 wt % to about 95 wt % water. The water-miscible hydroxyl-containing solvent can be selected from methyl lactate, ethyl lactate, propyl lactate, 2-methyl 2,4-pentandiol, 1,2 hexanediol, 1,2 pentanediol, or a mixture thereof. The binding agent can include from about 2 wt % to about 30 wt % polymer binder dispersed in an aqueous liquid vehicle.

What is claimed is: 
     
         1 . A multi-fluid kit for three-dimensional printing comprising:
 a wetting agent including:
 from about 5 wt % to about 80 wt % water-miscible hydroxyl-containing solvent selected from methyl lactate, ethyl lactate, propyl lactate, 2-methyl 2,4-pentandiol, 1,2 hexanediol, 1,2 pentanediol, or a mixture thereof; and 
 from about 20 wt % to about 95 wt % water; and 
   a binding agent including from about 2 wt % to about 30 wt % polymer binder and an aqueous liquid vehicle.   
     
     
         2 . The multi-fluid kit of  claim 1 , wherein the wetting agent includes from about 20 wt % to about 60 wt % of the water-miscible hydroxyl-containing solvent. 
     
     
         3 . The multi-fluid kit of  claim 1 , wherein the water-miscible hydroxyl-containing solvent includes ethyl lactate, 2-methyl 2,4-pentandiol, or a combination thereof. 
     
     
         4 . The multi-fluid kit of  claim 1 , wherein the polymer binder includes latex polymer particles having an average particle size from about 3 nm to about 1 μm. 
     
     
         5 . A three-dimensional printing kit comprising:
 wetting agent including:
 from about 5 wt % to about 80 wt % water-miscible hydroxyl-containing solvent selected from methyl lactate, ethyl lactate, propyl lactate, 2-methyl 2,4-pentandiol, 1,2 hexanediol, 1,2 pentanediol, or a mixture thereof; and 
 from about 20 wt % to about 95 wt % water; 
   a binding agent including from about 2 wt % to about 30 wt % polymer binder and an aqueous liquid vehicle; and   a particulate build material including from about 80 wt % to 100 wt % metal particles.   
     
     
         6 . The three-dimensional printing kit of  claim 5 , wherein the wetting agent includes from about 20 wt % to about 60 wt % of the water-miscible hydroxyl-containing solvent. 
     
     
         7 . The three-dimensional printing kit of  claim 5 , wherein the water-miscible hydroxyl-containing solvent includes ethyl lactate, 2-methyl 2,4-pentandiol, or a mixture thereof. 
     
     
         8 . The three-dimensional printing kit of  claim 5 , wherein the particulate build material includes from about 95 wt % to 100 wt % of the metal particles, and the metal particles have D50 particle size from about 3 μm to about 100 μm. 
     
     
         9 . A method of three-dimensional printing comprising:
 iteratively applying individual build material layers of a particulate build material onto a powder bed, the particulate build material from about 80 wt % to 100 wt % metal particles;   based on a three-dimensional object model, iteratively applying a wetting agent to individual build material layers, wherein the wetting agent includes from about 5 wt % to about 80 wt % water-miscible hydroxyl-containing solvent selected from methyl lactate, ethyl lactate, propyl lactate, 2-methyl 2,4-pentandiol, 1,2 hexanediol, 1,2 pentanediol, or a mixture thereof; and from about 20 wt % to about 95 wt % water; and   based on a three-dimensional object model, iteratively and selectively applying a binding agent to individual build material layers at a location where the wetting agent was applied to define individually patterned object layers that become adhered to one another to form a layered green body object, wherein the binding agent includes from about 2 wt % to about 30 wt % polymer binder and an aqueous liquid vehicle.   
     
     
         10 . The method of  claim 9 , further comprising heating the layered green body object to a temperature ranging from about 100° C. to about 200° C. to cure the layered green body object. 
     
     
         11 . The method of  claim 9 , wherein the wetting agent includes from about 20 wt % to about 60 wt % of the water-miscible hydroxyl-containing solvent, and the water-miscible hydroxyl-containing solvent includes ethyl lactate, 2-methyl 2,4-pentandiol, or a mixture thereof. 
     
     
         12 . The method of  claim 9 , wherein the wetting agent and the binding agent are applied at the location at a weight ratio from about 1:5 to about 5:1. 
     
     
         13 . The method of  claim 9 , wherein the wetting agent and the binding agent are collectively applied as total fluid agent at the location at a total fluid agent to particulate build material weight ratio from about 3:97 to about 10:90. 
     
     
         14 . The method of  claim 9 , further comprising heating the particulate build material to a temperature ranging from about 40° C. to about 100° C. during application of the wetting agent and the binding to the individual layers. 
     
     
         15 . The method of  claim 9 , further comprising sintering the layered green body object to form a heat-fused metal article.